/usr/lib/x86_64-linux-gnu/libdapserver.so.7 is in libdapserver7v5 3.18.2-2+deb9u1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libdapserver.so.7.6.5
/usr/lib/x86_64-linux-gnu/libdapserver.so.7.6.5